• Journal of the Semiconductor & Display Technology
• /
• v.8 no.4
• /
• pp.37-42
• /
• 2009

The performance of an OLED(organic luminescent emitting device) fabrication system strongly depends on the design of the evaporation cell-source. Trends in display sizes have hauled the enlargement of mother glass substrates. The enlargement of substrates requires the improvement and the enlargement of the effusion cell-source for OLED evaporation process. The deposited layers should be as uniform as possible, and therefore it is important to know the effusion profile of the molecules emitted from the cell-source. Conventional 2D DSMC algorithm cannot be used for simulating the new concept cell-source design, such as a linear source. This work concerns the development of 3D DSMC (direct simulation Monte Carlo) analysis for simulating the behavior of the evaporation cell-sources. In this paper, the 3D DSMC algorithm was developed and the film thickness profiles were obtained by the numerical analysis.

• Korean Journal of Optics and Photonics
• /
• v.18 no.1
• /
• pp.24-30
• /
• 2007

We have studied depth conversion of a reconstructed image by means of recombination of the elemental images in the integral imaging system for 3D display. With the recombination, depth conversion to the pseudoscopic, the orthoscopic, the real or the virtual as well as to arbitrary depth without any distortion is possible under proper conditions. The conditions on the recombinations for the depth conversion are theoretically derived. The reconstructed images using the converted elemental images are presented.

• Journal of the Semiconductor & Display Technology
• /
• v.12 no.3
• /
• pp.1-6
• /
• 2013

In many technical fields including electronics and display manufacturing processes, properties of coating liquids could be greatly enhanced by adding nanopowders and it requires efficient mixing techniques to achieve uniform dispersion of nanoparticles in liquids. This paper presents the three-dimensional CFD simulations on the flowfields of a highly viscous liquid in the large scale industrial mixer of impeller type. The effects of several important design and operation parameters such as impeller geometry, rotational speed, and degree of liquid viscosity are investigated to appreciate the mixing performance by examining the computational results for flow pattern of rotationally stirred liquid of high viscosity in the mixer.

• Journal of the Optical Society of Korea
• /
• v.20 no.1
• /
• pp.70-77
• /
• 2016

This paper proposes an optical system for complex holographic display that enhances the quality of the reconstructed three-dimensional image. This work focuses on a new design for an optical system and the evaluation of the complex holographic display, using a single spatial light modulator (SLM) and a circular grating. The optical system is based on a 4-f system in which the imaginary and real information of the hologram is displayed on concentric rectangular areas of the SLM and circular grating. Thus, this method overcomes the lack of accuracy in the pixel positions between two window holograms in previous studies, and achieves a higher intensity of the real object points of the reconstructed hologram than the original phase-reconstructed hologram. The proposed method provides approximately 30% less NMRS (Normal Root Mean Square) error, compared to previous systems, which is verified by both simulation and optical experiment.

• ETRI Journal
• /
• v.39 no.4
• /
• pp.480-492
• /
• 2017

A holographic display based on a viewing window enables the converging of a reconstruction wave into a viewing window by means of an optical system. Accordingly, a user can observe a reconstructed hologram image, even with a small diffraction angle. It is very difficult to manufacture an optical system with no aberrations; thus, it is inevitable that a certain amount of wave aberrations will exist. A viewing-window-based holographic display, therefore, always includes distortions in an image reconstructed from a hologram pattern. Compensating the distortions of a reconstructed image is a very important technical issue because it can dramatically improve the performance when reconstructing a digital three-dimensional content image from a hologram pattern. We therefore propose a method for suppressing image distortion by measuring and compensating the wave aberration calculated from a Zernike polynomial, which can represent arbitrary wave aberrations. Through our experimental configuration using only numerical calculations, our proposed method decreased the reconstructed image distortion by more than 28%.

• Korean Journal of Cognitive Science
• /
• v.14 no.1
• /
• pp.17-28
• /
• 2003

In order to provide natural images with a specified depth through three-dimensional display system, the stereo images should be similar to those projected from real environment as much as possible. Even when two persons see an identical scene, the binocular Parallax between two images of an object varies as a function of one's inter-pupilary distance (IPD). In this study, we investigated whether individual differences, such as IPD and accommodative vergence, would affect the perception of three dimensional scene provided by stereo-images. Results showed that a person's IPD is correlated with the limit of screen and binocular parallax for single vision, and affects the perceived depth of an object on fixation. More specifically, with longer IPD the limit of screen and binocular parallax for single vision is decreased, and the perceived depth is reduced. These results suggest that the screen and binocular parallax of an object should be calibrated with regard to users IPD to provide natural stereo-images with a specified depth and to Prevent double vision.

• Korean Journal of Optics and Photonics
• /
• v.26 no.5
• /
• pp.249-254
• /
• 2015

In this paper we propose a binocular holographic three-dimensional (3D) imaging system using optical scanning holography. To realize a binocular 3D holographic imaging system, we could acquire the complex holograms of a real object after designing a holographic display system based on interpupillary distance and pupil size, and these holograms could be optically reconstructed following numerical signal processing with an amplitude spatial light modulator. The proposed binocular 3D holographic imaging system using optical scanning holography was verified experimentally.

• Proceedings of the KIEE Conference
• /
• 2002.07c
• /
• pp.1628-1630
• /
• 2002

In this paper, we measured 3-dimensional temporal behavior of the light emitted from discharge cell of plasma display panel(PDP) as a function of the pressure using the scanned point detecting system. The detected light signal through the PM tube is sent on the oscilloscope and oscilloscope which is connected to PC with GPIB. The whole system is controlled by a PC. From the temporal behavior results, we could analyze the discharge behavior of panel with Ne-Xe(4%) mixing gas and 300torr, 400torr, 500torr pressure. The top view of panel shows that the discharge moves from inner edge of cathode electrode to outer cathode electrode forming arc type. At the 300torr, initial emission time is very fast. The side view of panel shows that the light is detected up to $150{\mu}m$ height of barrier rib. In the panel of 300torr, emission distribution is wider than the others.

• Korean Journal of Optics and Photonics
• /
• v.27 no.1
• /
• pp.41-46
• /
• 2016

An optical method to measure the three-dimensional (3D) shape of a surface with specular reflection is proposed. The proposed method is based on the analysis of the geometric path of the light from a point source, and the relative displacements of points in the reflection image. The 3D shape of a concave mirror is shown to be determined approximately via experiments, where the vision system consists of LED array illumination, a half-mirror, and an imaging sensor.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.18 no.12
• /
• pp.3055-3062
• /
• 2014

3D integral imaging technique with an active mask is capable of displaying real 3D images with high resolution in space. In this paper, we present a novel 3D/2D convertible integral imaging display system using an active mask. For the proposed method, the principles of 3D, 2D, and 3D/2D composed operations are explained according to the displayed images through two LCD panels. In 3D mode, the elemental images and the mask images are displayed in two display panels. On the other hand, the light source image and 2D image are displayed in 2D mode. In addition, 3D/2D mode is obtained using the spatial separation for 3D and 2D modes. To show the feasibility of the proposed method, we carry out the preliminary experiments and present the optical results.